Tet Offensive

The Tet Offensive was a major, large-scale offensive undertaken by the North Vietnamese PAVN and its Viet Cong guerrilla allies into South Vietnam during the Vietnamese Lunar New Year (Tet) celebrations. The offensive struck almost every city in South Vietnam, but it was repulsed with heavy losses. The Viet Cong suffered such heavy losses that North Vietnam was forced to commit a larger share of the communist alliance's forces in future offensives, and the North Vietnamese failed to provoke a popular uprising in South Vietnam. However, the near-success of the invasion and the communists' ambitious all-out offensive shocked the US public, which had been led to believe that the war was almost won; after the Tet Offensive, the public no longer believed that the US strategy was working, and believed the war to be unwinnable.

Background
In the fall of 1967, Communist Party of Vietnam First Secretary Le Duan began to plan a general offensive into South Vietnam to bring an end to the Vietnam War. North Vietnam's civilian population was becoming weary of the war due to Operation Rolling Thunder, so Le Duan decided to gamble on a highly ambitious plan to topple the Saigon government in one swift blow. North Vietnamese forces would invade South Vietnam from the DMZ and from Laos and Cambodia and attack cities and bases all over the south, while the Viet Cong would step up their guerrilla attacks; the ultimate goal was to provoke a general uprising against the US-backed Saigon government, crush South Vietnam, and force the US to withdraw its troops as a result. Le Duan purged those opposed to the plan, sending several former Viet Minh heroes, cautious CPV leaders, and party members opposed to the offensive to prison camps such as the Hanoi Hilton. Through to the end of 1967, the NVA and Viet Cong engaged the United States and the South Vietnamese ARVN in a series of "border battles" to pave the way for a surprise offensive in January. The surprise attacks would begin at the end of the month, at the start of the Tet celebrations. The Viet Cong were already infiltrating cities and towns, while tens of thousands of NVA troops were standing ready in South Vietnam, being covertly supplied by the North Vietnamese government in preparation for its most ambitious offensive yet. Meanwhile, the US and South Vietnamese forces had noticed signs of a coming storm, taking note of irregular communist troop movements, as well as captured plans to attack key South Vietnamese cities and captured tapes urging the South Vietnamese to rise up. MACV commander William Westmoreland predicted that the attack would occur before Tet, and that the US Marine Corps base at Khe Sanh would be the main target. 30,000 NVA troops gathered near Khe Sanh, the westernmost stronghold below the DMZ, held by just 6,000 Marines. However, Westmoreland was sure that the other targets would only be diversions. General Frederick Weyand wisely repositioned half of the troops along the Cambodian border to the outskirts of Saigon in case of an enemy attack.

Offensive
On 21 January 1968, the NVA began shelling Khe Sanh. When he learned of the attack on Khe Sanh, President Lyndon B. Johnson made the Joint Chiefs sign a pledge that the base would not fall, as he feared a repeat of the Battle of Dien Bien Phu. Westmoreland and Johnson's main assumption was false, however, as Khe Sanh was the sideshow, and the main event would be the assaults on the cities and towns of South Vietnam. However, Le Duan's basic assumptions were also to be tested, as the ARVN would have to collapse and the Southerners would have to join the revolution in order for the plan to succeed.

By 30 January, an informal 36-hour truce for Tet was in effect. Thousands of ARVN troops went home for the holiday, but neither the NVA nor the Viet Cong did. Instead, on the early morning hours of 31 January, 84,000 Viet Cong and NVA troops attacked 36 of South Vietnam's 44 provincial capitals, dozens of US and ARVN military bases, and the 6 largest cities in the country. In Saigon, Westmoreland mistook the first explosions as holiday firecrackers. His deputy commander Creighton Abrams was asleep, and his aides did not bother to wake him. Not a single top commander was present at Pentagon East, the MACV headquarters at Tan Son Nhut Airbase on the outskirts of Saigon, when mortars and rockets began cratering the runways. The Viet Cong spread out to attack specific targets in and around the capital, and the war finally came to the streets of Saigon. One Viet Cong squad made it all the way to the Presidential Palace, where they were stopped by ARVN tanks. The survivors holed up in a building across the street, where they were shot by ARVN troops and American MPs. Viet Cong units took heavy losses from US troops and determined ARVN forces across the city,